Because a therapeutic agent, for example pharmacological, genetic, or biological, may be ineffective or even toxic when delivered systemically, tools and methods for delivering therapeutic agents locally, that is, to a targeted tissue site, have been developed.
Many state-of-the art steerable catheters have lumens through which agents may be delivered. Rather than modifying state-of-the-art steerable catheter designs to integrally incorporate specific delivery mechanisms, such as means to inject agents into a tissue site, it is desirable to provide modular apparatuses, which can be coupled to any of such state-of-the-art steerable catheters and which include desired specific delivery mechanisms.